I transcode my movies and convert the PGS subtitle files to srt files. Whenever I watch one of my movies on an iPhone, iPad or AppleTV everything is fine but as soon as I open up the web browser or an NVIDIA Shield, I get these enormous subtitles and I have no idea how I can get rid of this issue for once and for all.
I usually convert my video to mp4 (m4v) and add the subtitles with Subler.